In a lot of ways, FBF animation has never been disrupted so much as just temporarily displaced by other techniques for reasons of efficiency. The animator still has to make good design decisions up front so that the figure construction works and objects move in a perceptually believable way. Everything else - whether it's rotoscoping or tweening or something else - assists, but doesn't aim to truly emulate the thought process that a traditional animator uses, so you get different results that are often more mechanically precise but less interesting to watch.